Problem: Evaluate the following expression when $x = 8$ and $y = 2$. $9$ $x$ $^2 + 5$ $y$ $ - 7$
Solution: Substitute $8$ for ${x}$ and $2$ for ${y}$ $ = 9{(8)}^2 + 5{(2)} - 7 $ Remember order of operations. Evaluate the exponent before you multiply. $ = 9(64) + 5{(2)} - 7 $ $ = 576 + 10 - 7 $ $ = 579$